I am analyzing some bird data that were generated from 10-minute point counts in different habitat types, in different regions, from 2009 to 2018. But not all areas have data every year.
I was following the example of Montrave by Buckland ( 2006 ), for multispecies analysis. But I had a question. If you want to analyze point transect data, the variable Effort - length of the transect (km) that is used to correct effort in this exercise, what data should be used for the sampling points? I don´t have the length of the transects.
Another doubt I have is whether, given that there are no data for each year in each region, the information should be filtered by region and year? As a way to standardize ? Or should I filter the data for specie instead?
It is my first time analyzing this data, I really would appreciate your advice.